Processing machines for electroplating and like operations



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Feb. 28, 1956 P. A. HAucK 2,736,441

PROCESSING MACHINES FOR ELECTROPLATING AND LIKE OPERATIONS Filed NOV. 15, 1954 2 Sheets-Sheet l INVE OR lue 4. Mel. Mam/15M ATTORNEY5' Feb. 28, 1956 P. A. HAUCK PROCESSING MACHINES FOR ELECTROPLATING AND LIKE OPERATIONS Filed Nov. 15, 1954 2 Sheets-Sheet 2 FIG. 5

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United States Patent PROCESSING MACHINES FOR ELECTROPLATING AND LIKE OPERATIONS Paul A. Hauck, Union, N. 5., assignor to Hanson-Van Winkle-.Munning Company, Matawan, N. 3., a corporation of New Jersey Application'November 15, I95'4,ISerial No. 468,686 I 9 Claims. :(Cl. 214-459) This invention relates to processingmachines, in which workpieces are automatically transported 'to successive stations, where they undergo difierent processing treat- :ments, and, more particularly, the invention is concerned with improvements in processing :machines,.i.n which some of the treatments given the workpieces take longer than others, so that the workpiece carriers must remain at rest at the stations for periods of difierent length. The processing machine .of the invention may 'be used for various purposes, but, since all of the advantages of the invention are realized in its application to electroplating, a machine embodying the invention and suitable for .such use will'be illustrated and described for purposes of explanation.

Automatic electroplating machines commonly include a plurality of preparation tanks for cleaning, rinsing, and like treatments of the workpieces, one or :more plating tanks, and a plurality of tanks for finishing treatments, such as reclaim rinsing, hot .rinsing, etc. In such machines as usually constructed, the workpiece carriers are advanced along ahe machine step by step by a conveyor, and an elevator operating in timed relation with the conveyor raises and lowers the carriers, so that they may be moved in raised position over the end of each tank and then lowered to immerse their workpieces in the .following tank. Most of the preparation and :finishing treatments are 'of short duration, so that the workpieces are lowered 'into the tanks and then raised therefrom on the next ascent of the elevator. The plating operation requires a longer time and, accordingly, insome machines, which function ina skip-stop cycle, :the plating is carried on in tanks having a number of plating stations and, after the workpiece carriers have been moved along the preparation tanks in the "usual Way, they 'are transferred .rfrom .the ilast preparation tank to the plating stations :in

sequence, until all the stations are .filled. lnthis aoperaation, the carrier first removed from the last preparation tank is normally delivered to a plating station atone-end .of the series, for example, the last station in the last .tank, .and, when carriers have been delivered to all the stations, the plating of the workpieces .at the last station has been completed. Accordingly, when the elevator lowers a carrier into the first plating station, the elevator on its ascent .raises the carrier trom the last station, so that it may be conveyed to the finishing tanks. Theoperation then proceeds with the elevator lowering a carrier into a ,plating station and then, .as .it rises, raising the carrier from the adjacent station :toward the last preparation tank. .If desired, the plating stations may be 'filled and emptied in the .reverse order.

'The conveyor employed in a. skip-stop electroplating machine commonly includes one or more endless chains and means, such as yokes,, mounted .on the chains invposition to engage the workpiece carriers and move them along horizontal tracks 'on the elevator structure. The conveyor can be controlled in various ways 'to stop it with 'a workpiece carrier in registry with a station in a plating tank, into which the workpieces on the carrier "are to be ice lowered, and one arrangement for the purpose includes limit switches at the plating "stat-ions. 'Thellimit switches are operated by means carried by the conveyor and are made e'fiective in the proper order by a control mechanism to stop the conveyor with 'a-carrier thereon registering with the desired plating station. When the conveyor is stopped with a carrierabove -a plating station, -a yoke on the conveyor should lie above each of the other plating stations in position to :receive a carrier raised by the :elevator from any of the stations.

The tolerances in the manufacture of a chain conveyor result in variations in the spacing between yokes, which affect the registry of the yokes with the plating stations. Variations in spacing between yokes, which are adjacent to or .relatively near :each other, cause no diffi'culty, but, when a relatively long chain conveyor is stopped by a limit switch at the plating station atone end of the series with a yoke on the :conveyor :in proper registry with that station, the yoke on the conveyor above the other end plating station may be .out of fregistry with that station by a substantial distance. The problem of variations in chain length cannot be solved by changing the position :of one of the end stations, since this would prevent conveyor yokes from registering simultaneously with that station and the :one next 'to it. As will be evident, errors or variations in chain :length increase with Wear and the difiiculties in registry arising therefrom, accordingly, become more acute.

The present invention is directed :to the provision of a processing machine operating in a skip-stop cycle, in which means are provided for counteracting the effect of variations in chain length resulting from manufacturing tolerances, from wear, or :from both causes. In the machine of the invention, the plating stations are disposed at a uniform spacing and the yokes or other pusher means on the chain conveyor are correspondingly spaced. In order to insure that a carrier raised from the plating station at one end of the series will register with the yoke above that station, when the conveyor has been stopped by the limit switch at the station at the other end of the series, means are provided for moving the carrier horizontally as .it is being moved vertically by the elevator, the horizontal movement of the carrier being such as to compensate for the variation in chain length and to insure that the carrier will be properly engaged with the yoke on the conveyor, by which it is to be advanced.

For a better understanding of the invention, reference may be :made to the accompanying drawings, in which .Fig. 1 is a diagrammatic elevational view of a part of an electroplating machine operating on .a skip-stop cycle;

Fig. 2 is a sectional view of the machine on the line 22 of 'Fig. 3,;

Fig. 3 is .a view inside elevation of one form of the means employed in the machine for counteracting the effect of errors in chain conveyor length; and

Figs. 4 and 5 are views in side elevation of modified forms of the means, shown in Fig.3.

The electroplating machine shown diagrammatically in Fig. 1 includes a series or" preparation tanks Id, 11, in which workpieces are subjected to such treatments as cleaning, pickling, rinsing, etc. The workpiece carriers 12 are advanced stepwise .along the tanks, while supported on horizontal tracks on .an elevator structure 13, by means of yokes '14 on a chain conveyor 15 and, as a carrier comes into registry with each tank, the elevator is lowered to cause the workpieces on the carrier to be immersed :in the solution in the tank and the carrier is raised, when the elevator next ascends. The tanks are ordinarily of unit size and have a spacing equal to the length of a step of *themonveyor movement, 'althoughth' tanks may be of multiple unit size, if desired.

' The plating tan'ks lie beyond the last preparation tank 11 and five such tanks designated 16, 17, 18, 19, and are shown, although it is to be understood that more or less plating tanks may be employed as required. In the machine illustrated, the workpiece carriers 12 are deposited singly in the last preparation tank 11 by elevator 13 and the carriers are conveyed in pairs to and from the plating tanks. The tank 11 is, accordingly, provided with means, by which carriers lowered singly into that tank may be combined, so that pairs of the carriers can be raised for movement along the plating tanks. The mechanism employed for thus combining the carriers in the tank 11 may be that disclosed in the co-pending application of Todd and Hauck, Ser. No. 457,255, filed September 20, 1954, now Patent No. 2,710,698, issued June 14, 1955.

The pairs of carriers are raised from tank 11 by an elevator structure 21 having tracks extending along the plating tanks and over part of the first of the finishing tanks 22, 23, etc., and the carriers are moved along the tracks by yokes 24 on a conveyor 25. Each of the plating tanks illustrated has four plating stations and the top of each tank is provided with a saddle 26 at each side of the tank at each station. When a pair of carriers has been advanced by conveyor into registry with a pair of plating stations in a tank, the operating arm of a limit switch, such as the switch 27 mounted above the first two plating stations 16a, 16b in tank 16, is engaged by one of the carriers and the switch is actuated to stop the conveyor with the carriers in registry with the plating stations. The carriers are then lowered by the elevator 21 to rest upon saddles 26 at the stations and the elevator releases the carriers and then rises. In the ascent of the elevator, it raises another pair of carriers from their plating stations and these carriers are then advanced by conveyor yokes 24 to positions over the first finishing tank 22. Upon the next descent of the elevator, the carriers removed from the plating stations are left behind in tank 22. The pairs of carriers deposited in tank 22 are separated by a suitable mechanism, such as that shown in the Todd and Hauck application above identified, so that the carriers can be raised singly from tank 22 by an elevator 28 and advanced along the remaining finishing tanks by a conveyor 29 having yokes 34 The elevator 21 is of such construction that it leaves at plating stations all carriers lowered thereby, but raises the carriers from the plating stations selectively. In order that the elevator may function as described, it includes selectively operable lifter elements, which may be cam-operated flippers of the type disclosed in the Hauck and Todd patent. The lifter elements illustrated are those of the patent and the elevator is provided with beams 31 extending along opposite sides of the tanks and carrying angle irons 32 forming the tracks, on which the wheels 12a of the carriers roll. At each plating station, each track is cut away to form an opening and a lifter element 33 pivoted on beam 31 lies within the opening. Each element has a Weighted arm 34 normally holding the element against the beam, so that the element does not close the opening in the track. In order to make the elements effective to raise a carrier, a cam arm 35 is pivotally mounted at each side of each tank at each plating station therein. Each cam arm is actuated by a toggle 36 operated by the plunger 37:: of a solenoid 37 and, when the solenoids at a plating station are energized, their cam arms are swung into the paths of the arms of the associated lifter elements. When the elevator rises, the cam arms are engaged by the element arms and cause the latter to swing the elements into effective position to lift the carrier from the plating station. The solenoids are selectively energized by the control mechanism of the machine, so that the pairs of carriers will be raised from the plating stations in the desired sequence.

In one mode of operation of the apparatus described,

when a pair of carriers are to be transferred from tank 11 to the first two plating stations 16a, 16b of tank 16, the carriers are raised from tank 11 by lifter elements of the elevator 21 and are then moved along the tracks on the elevator by yokes 24 of the conveyor 25, until the conveyor is stopped by the limit switch with the carriers in registry with the saddles of the plating stations. At this time, a pair of yokes 24a, 24b on the conveyor lie above the saddles of the last two plating stations 200, 2th! of tank 29, but, because of chain length variation, the yokes 24a, 24b lie otfset from the plating stations 2%, 20d, in the direction of conveyor movement. When the elevator has deposited carriers in stations 16a, 16b and then raises a pair of carriers from stations 20c, 20d, the latter carriers will not register properly with yokes 24a, 2411, because of chain length error, and the lack of registry may be such that the carriers cannot be advanced along the elevator tracks by those yokes.

In the machine illustrated, the difliculties above described are overcome by mechanism, which causes carriers moving vertically with the elevator to be given a horizontal movement sufficient to correct for the chain error. The mechanism may be of difierent constructions and the form illustrated in Fig. 3 comprises a cam arm 33, which is pivotally mounted on a fixed part 39 of the machine frame and can be swung in a vertical plane parallel to the direction of conveyor movement by a toggle 40 having one end connected to the cam arm and the other pivotally mounted on a part 41 of the frame. The toggle is actuated by the plunger 52a of a solenoid 42 and, when the solenoid is de-energized, the plunger moves down, the toggle is shortened, and arm 33 moves to inoperative position. When the solenoid is energized, the toggle is straightened and the arm 38 becomes efiective.

A pair of devices, as shown in Fig. 3, are mounted on opposite sides of tank 20 at each of the plating stations 29c, 20:13. The devices are so disposed at each station, for example, station 290, that, when they are inoperative, their arms lie out of the path of travel P1 of a carrier 12 being lowered from a yoke on conveyor 25, when the conveyor has been stopped by the limit switch for the plating stations 20c, 20d. As pointed out above, when the conveyor is stopped by the limit switch 27 for plating stations 16a, 16b, the yoke 24a lies out of registry with path P1 by a distance E, which represents the chain error. The solenoids 42 are energized simultaneously with the energization of the solenoids 37 of the lifter elements 33 at station 20c and the cam arms 38 are then moved across the path P1. As the elevator rises, the carrier 12 supported on lifter elements 33 strikes the arms 38 and is moved horizontally thereby on the lifter elements 33 until the carrier passes by the end of arms 38. Such horizontal movement of the carrier etiected by the arms 38 is equal in length to distance E and moves the carrier on the lifter elements to a position in registry with yoke 24a on the conveyor, the carrier traversing the path P2 in its rising movement. The action of the devices at station 20d is the same as that described, so that, when the carriers are raised from stations 20c and 20d, they are both moved horizontally to correct for the chain error and are brought into registry with their respective yokes 24a, 24b. In order that the carriers may be moved on the lifter elements without over-travel, these elements are provided with ribs 33a on their tops.

The device shown in Fig. 3 operates to cause a horizontal movement of a carrier, while it is being raised by the elevator, but the horizontal shifting of the carrier may be accomplished, while the carrier is being lowered by the elevator, by the form of the mechanism shown in Fig. 4. The Fig. 4 device includes a cam plate 43 mounted on a standard 44 secured to a suitable part of the machine by slot and bolt connections indicated at 45, the connections permitting the plate to be adjusted horistation 200.

reener zontally. Such a plate 43 is provided on each .side of the tanks at each plating station where vlack -.of registry of a carrier with a yoke on .the conveyor may develop. Eachplate 43 .has a surface 43a inclined -to the vertical and the plates are so .mounted that their surfaces 43a lie in :thepath P3 of a carrier 12 being lowered from a yoke on the conveyor to a plating station, such as the When a carrieris'to be delivered to plating station 20c, the conveyor is stopped by thelimit switch ;at that-plating station, but the path P3 of descent of the carrier is offset by-the chain error Efrom the path P4 along which the carrier should be .raised ,to register with the yokes 24a, which will advance the carrierto the ,tank12. The position of plates 43 is such :that, as ,a :carrier moves down path Pa, it will engage the surfaces 43a on 'the plates and be moved horizontally along the lifter elements by the distance :E. The carrier is then left at station .200 in the adjusted iposition described and, when the carrier is finally raised from station .200, it will move along path P4 and be brought in registry with the yokes 24a of the conveyor.

A third form of the mechanism for moving carriers to compensate for chain error is illustrated 'in Fig. 5 and it includes a .cam arm 46 depending pivotally from =afixed part '47 of the machine structure and held in a desired position of adjustment by .aistop bar 48 secured .adjustably on a part 49 of :the machine frame by .boltand slot connections indicated at :50. The lower end of the arm 46 is cut off at an angle totprovide an inclined cam surface 46a and the arm is mounted, so that it lies with the cam surface 46a extending downwardly below the 'level of the yokes .on the conveyor.

vA pair of the arms 46 .andstops 48 are mounted at each plating station, such as :station 200, Where the problem of registration of :a carrier .12 with yokes 24a on the conveyor 25 occurs, and the arms lie in the path of carriers being moved along tracks 32 .and can be swung by the carriers to permit the carriers :to pass by. When a carrier-is to be lowered to the plating station, the'carrier lies in registry *with the .station and is holding arm 46 away vfrom stop 48. The carrier :moves down along the straight path P5 until it is clear of the arm, after which the arm swings back against the stop and its cam surface lies across the path P5. When the carrier is raised from the station, it moves upwardly along path {P5, until it engages the surface 46a on arm 46, whereupon it is :moved horizontally on its lifter elements 33, .until it is brought .into proper registry with conveyor yokes 24a, which are to advance it.

The electroplating machine illustrated includes an elevator with horizontal tracks and the carriers are moved along the track by pushers on the conveyor, such pushers having the form of yokes. It is to be understood that the utility of the invention is not limited to its use with conveying and elevating means of the specific construction described and the invention may be employed to advantage with processing machines of other constructions, which operate in a skip-stop cycle.

In the machine described in which the lowering of workpiece carriers into the first two plating stations 16a, 16b is fbllowed by the raising of a pair of carriers from the last two stations 20c, 20d, the chain error has caused displacement of the yokes 24a, 24b in the direction of conveyor movement. Accordingly, the mechanism for correcting the chain error acts to impart a movement in the direction of travel of the conveyor to the carriers, which are to be moved to the finishing tanks by yokes 24a, 24b. If the carriers are loaded into and removed from the plating stations in the reverse order, the stopping of the conveyor at the last two plating stations 20c, 20d by the limit switch for those stations and the lowering of the carriers into the stations by the elevator will be followed by the raising of carriers from stations 16a, 16b, when the elevator ascends. Under such conditions,

6 the yokesabove stations 16a, 16b will be out -of registry with the stations becauseof the chain error and the displacement -will he in a direction opposite .to :that of .conveyor movement. The mechanism -.of the invention will be then used to ,produce a corresponding horizontal movement of the carriers, that is, a movement opposite to that produced by the mechanism installed as illustrated.

.I claim:

.1. A processing machine, which comprises carriers for workpieces to .be treated, a series of treatment stations, an elevator for lowering the carriers to and raising them from'the stations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means on the chain engageable with .-the carriers raised by 'the lifter elements, and means independent of the conveyor at at least one station for moving individual carriers horizontally .into alignment with carrier-engaging means at .rest at said station during movement of the carriers with ithe elevator :at said station.

2. A processing machine, which comprises carriers for workpieces to be treated, a series of treatment stations, an elevator .for lowering the carriers to and raising :them from thestations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stat-ions operable :to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including .a chain and means on the chain engageable with the carriers raised by the lifter elements, and means independent of the conveyor at at least one station 'for moving individual carriers horizontally 'on the elements into alignment with carrier-engagingmeans at rest at said station, while the carriersare supported by the elements and being moved by the elevator.

3. .A processing machine, which comprises carriers for workpieces to be treated, a series of treatment stations, an elevator for lowering the :carriers to and :raising them from the stations, the elevator Jhaving horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements -on the .elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means .on .the chain engageable with the carriers :raised by the lifter elements, and cam means independent of the conveyor at at least one station engageable by individual carriers during their vertical movement with the elevator at said station for moving said carriers horizontally into alignment with carrierengaging means at rest at said station.

4. A processing machine, which comprises carriers for workpieces to be treated, a series of treatment stations, an elevator for lowering the carriers to and raising them from the stations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means on the chain engageable with the carriers raised by the lifter elements, and cam means independent of the conveyor at at least one station adapted to be engaged by individual carriers supported on lifter elements at that station, said cam means being effective to move the carriers horizontally into alignment with carrier-engaging means at rest at that station during ascending movement of the carriers with the elevator.

5. A processing machine, which comprises carriers for workpieces to be treated, a series of treatment stations,

an elevator for lowering the carriers to and raising them from the stations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means on the chain engageable with the carriers raised by the lifter elements, and cam means independent of the conveyor at at least one station adapted to he engaged by individual carriers supported on lifter elements at that station, said cam means being effective to move the carriers horizontally to a predetermined work position during their descending movement only with the elevator.

6. A processing machine, which comprises carriers for workpieces to be treated, a series of treatment stations, an elevator for lowering the carriers to and raising them from the stations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means on the chain engageable with the carriers, and cam means at at least one station engageable by individual carriers during their vertical movement with the elevator at said station and moving said carriers horizontally, said cam means including a movable cam arm normally in inoperative position and a solenoid for moving the cam arm into position to be engaged by a carrier and to move the latter.

7. A processing machine which comprises carriers for workpieces to be treated, a series of treatment stations, an elevator for lowering the carriers to and raising them from the stations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means on the chain engageable with the carriers, and cam means at at least one station engageable by individual carriers during their vertical movement with the elevator at said station and moving said carriers horizontally, said cam means including a movable cam arm normally in inoperative position, a toggle having one end fixed and the other connected to the cam arm, and a solenoid having a plunger connected to the joint between the ends of the toggle, the energization of the solenoid causing the plunger to increase the overall length of the toggle and move the cam arm into operative position.

8. A processing machine, which comprises carriers for workpieces to be treated, a series of treatment stations, an elevator for lowering the carriers to and raising them from the stations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means on the chain engageable with the carriers, and means at at least one station for moving individual carriers horizontally during their movement with the elevator at said station, said means including a pivotally mounted arm lying in position to be engaged and swung aside by a carrier descending with the elevator, the arm having a cam surface engageable by the carrier ascending with the elevator, and means for holding the arm against movement by an ascending carrier engaging the cam surface, the carrier being moved horizontally during its ascent by said surface.

9. A processing machine, which comprises carriers for workpieces to be treated, a series of treatment stations, an elevator for lowering the carriers to and raising them from the stations, the elevator having horizontal members extending along the stations and providing supports for horizontal movement of the carriers, lifter elements on the elevator at the stations operable to raise individual carriers selectively with the elevator, a conveyor for advancing the carriers along the supports, the conveyor including a chain and means on the chain engageable with the carriers, and cam means at at least one station engageable by individual carriers during their vertical movement with the elevator at said station and moving said carriers horizontally, said cam means including an arm mounted for pivotal movement and having a cam surface, the arm being movable by carriers being advanced by the conveyor and being restored to its original position by gravity, and means for holding the arm with its cam surface in position to engage a carrier being raised by the elevator and to move the carrier horizontally.

References Cited in the file of this patent UNITED STATES PATENTS 1,597,862 Miller Aug. 31, 1926 2,605,882 Curtis Aug. 5, 1952 2,624,440 Hornberger Jan. 6, 1953 2,671,861 Bullard III Mar. 9, 1954 

